1. Field of the Invention
The present invention relates to polymerization by sol-gel process and particularly to sol-gel templates that are formed with the infusion of gas bubbles to create a desired pattern of nanosize pores in the gel-matrix template.
2. Description of the Related Art
With the advent of nanotechnology, porous polymeric structures having nanosize pores have become structures of much value and interest. They may be used in numerous applications, including enzyme immobilization, biocatalysts, biosensors, solid oxide fuel cells, oxygen sensors, adsorbents, catalyst supports, electrode materials, energy storage devices, drug carriers, column packing materials for chromatography, etc. This novel gas templating method can be very useful in designing and tailoring the pore structures of polymeric materials, polymer-based carbons, and gels (e.g., resorcinol-formaldehyde gels, including aerogels, xerogels, cryogels, carbon aerogels, carbon xerogels, etc.) in a controlled and easy manner.
Recently, there has been some interest in using bubbles of gas to aid in the design and tailoring of gel templates. However, current methods rely upon the use of chemical precursors that react within the gel to form gas bubbles (which are sometimes designed to “explode” or burst within the gel) or the electrochemical generation of gas bubbles within the gel. The problems with such methods are that they often leave residues of unreacted precursors, or they leave a residue of solid reaction by-products, result in distorted pore sizes, and such methods are difficult to control the size of the resulting pores and the distribution of the resulting pores within the gel.
Thus, a sol-gel templates formed with the infusion of gas bubbles solving the aforementioned problems is desired.